What is the greatest common factor of $36$ and $28$ ? Another way to say this is: $\operatorname{gcf}(36, 28) = {?}$
Answer: The greatest common factor is the largest number that is a factor of both $36$ and $28$ The factors of $36$ are $1$ $2$ $3$ $4$ $6$ $9$ $12$ $18$ , and $36$ The factors of $28$ are $1$ $2$ $4$ $7$ $14$ , and $28$ Thus, the greatest common factor of $36$ and $28$ is $4$. $\operatorname{gcf}(36, 28) = 4$